Reflecting resin sheet, light emitting diode device and producing method thereof

ABSTRACT

A reflecting resin sheet provides a reflecting resin layer at the side of a light emitting diode element. The reflecting resin sheet includes a release substrate and the reflecting resin layer provided on one surface in a thickness direction of the release substrate. The reflecting resin layer is formed corresponding to the light emitting diode element so as to be capable of being in close contact with the light emitting diode element.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent ApplicationNo. 2011-089922 filed on Apr. 14, 2011, the contents of which are herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a reflecting resin sheet, a lightemitting diode device, and a producing method thereof, to be specific,to a producing method of a light emitting diode device, a reflectingresin sheet used in the producing method, and a light emitting diodedevice obtained by the producing method of the light emitting diodedevice.

2. Description of Related Art

In recent years, as a light emitting device that is capable of emittinghigh-energy light, a white light emitting device has been known. In thewhite light emitting device, for example, a diode board; an LED (lightemitting diode) laminated thereon, emitting blue light; a phosphor layerthat can convert the blue light into yellow light and covers the LED;and an encapsulating layer that encapsulates the LED are provided. Thewhite light emitting device emits high-energy white light by colormixing of the blue light emitted from the LED, which is encapsulated bythe encapsulating layer and to which electric power is supplied from thediode board, transmitting through the encapsulating layer and thephosphor layer, and the yellow light that is converted in wavelengthfrom a part of the blue light in the phosphor layer.

As a method for producing the white light emitting device, for example,the following method has been proposed (ref: for example, JapaneseUnexamined Patent Publication No. 2005-191420).

The proposed method is as follows. That is, a base, which has a boardportion and a white reflecting frame portion protruding from thecircumference portion thereof toward the upper side, is first formed.Next, a semiconductor light emitting element is subjected to a wirebonding in a bottom portion of a concave portion, which is formed at thecenter of the board portion by the reflecting frame portion, so as to bespaced apart from the inner side of the reflecting frame portion.

Next, a mixture of a phosphor and an epoxy resin in a liquid state isfilled in the concave portion by application, subsequently the phosphoris spontaneously precipitated in the bottom portion of the concaveportion, and then the epoxy resin is heat cured.

In the white light emitting device obtained by the method proposed inJapanese Unexamined Patent Publication No. 2005-191420, the phosphorlayer (a wavelength conversion layer) that contains the phosphor formedby a precipitation at high concentrations is defined in a region at theupper side of the semiconductor light emitting element and anencapsulating portion that contains the epoxy resin at highconcentrations is defined in a region at the upper side of the phosphorlayer.

In the white light emitting device, the semiconductor light emittingelement radially emits the blue light. Of the emitted blue light, a partthereof emitted from the semiconductor light emitting element toward theupper side is converted into the yellow light in the phosphor layer andthe remaining light transmits through the phosphor layer. The blue lightemitted from the semiconductor light emitting element toward the side isreflected at the reflecting frame portion and then toward the upperside. The white light emitting device in Japanese Unexamined PatentPublication No. 2005-191420 emits the white light by color mixing of theblue light and the yellow light.

SUMMARY OF THE INVENTION

However, in the white light emitting device obtained by the producingmethod in Japanese Unexamined Patent Publication No. 2005-191420, thereis a disadvantage that the semiconductor light emitting element isspaced apart from the reflecting frame portion, so that a part of thelight emitted from the semiconductor light emitting element toward theside is absorbed in the encapsulating portion before being reflected atthe reflecting frame portion and as a result, extraction efficiency ofthe light is reduced.

It is an object of the present invention to provide a light emittingdiode device that is capable of improving extraction efficiency oflight, a producing method thereof, and a reflecting resin sheet used inthe producing method.

A reflecting resin sheet of the present invention, for providing areflecting resin layer at the side of a light emitting diode element,includes a release substrate and the reflecting resin layer provided onone surface in a thickness direction of the release substrate, whereinthe reflecting resin layer is formed corresponding to the light emittingdiode element so as to be capable of being in close contact with thelight emitting diode element.

In the reflecting resin sheet of the present invention, it is preferablethat at one surface in the thickness direction of the release substrate,a portion in which the reflecting resin layer is provided is dentedtoward the other side in the thickness direction.

The method for producing a reflecting resin sheet of the presentinvention includes the steps of preparing the above-described reflectingresin sheet by providing a reflecting resin layer on one surface in athickness direction of a release substrate, providing a light emittingdiode element on one surface in the thickness direction of a diodeboard, and laminating the reflecting resin sheet on the diode board sothat the reflecting resin layer is in close contact with the sidesurface of the light emitting diode element.

In the method for producing the light emitting diode device of thepresent invention, it is preferable that in the step of laminating thereflecting resin sheet on the diode board, an exposed portion that isexposed from the reflecting resin layer in the release substrate isallowed to be in close contact with one surface in the thicknessdirection of the light emitting diode element.

In the method for producing the light emitting diode device of thepresent invention, it is preferable that the step of preparing thereflecting resin sheet includes the steps of disposing a mask where apattern including a plurality of covering portions disposed at spacedintervals to each other so as to correspond to the exposed portion and abridge portion that is disposed between the covering portions is formedon one side in the thickness direction of the release substrate so thatthe covering portion is opposed to the exposed portion, forming thereflecting resin layer in an opposite pattern to that of the coveringportion by applying a reflecting resin composition for forming thereflecting resin layer onto the release substrate via the mask, andremoving the mask.

The method for producing a light emitting diode device of the presentinvention includes the steps of providing a light emitting diode elementon one surface in a thickness direction of a base member, providing areflecting resin layer, on one surface in the thickness direction of thebase member, at the side of the light emitting diode element, andallowing a concave portion of a pressing member that is formed to bedented toward the other side in the thickness direction corresponding tothe reflecting resin layer to press the reflecting resin layer, so thatthe reflecting resin layer is in close contact with the side surface ofthe light emitting diode element.

In the method for producing the light emitting diode device of thepresent invention, it is preferable that the step of providing thereflecting resin layer includes the steps of disposing a mask where apattern including a plurality of covering portions disposed at spacedintervals to each other so as to correspond to the light emitting diodeelement and a bridge portion that is disposed between the coveringportions is formed on one side in the thickness direction of the basemember so that the covering portion is opposed to the light emittingdiode element, forming the reflecting resin layer in an opposite patternto that of the covering portion by applying a reflecting resincomposition for forming the reflecting resin layer onto the base membervia the mask, and removing the mask.

A light emitting diode device of the present invention includes a diodeboard, a light emitting diode element provided on one surface in athickness direction of the diode board, and a reflecting resin layerthat is in close contact with the side surface of the light emittingdiode element.

In the light emitting diode device of the present invention, it ispreferable that the reflecting resin layer is formed so that thethickness thereof is thicker than that of the light emitting diodeelement.

In the light emitting diode device of the present invention, it ispreferable that the light emitting diode device further includes aphosphor layer formed on one surface in the thickness direction of thelight emitting diode element.

According to the method for producing the light emitting diode device ofthe present invention using the reflecting resin sheet of the presentinvention, the reflecting resin sheet is laminated on the diode board sothat the reflecting resin layer is in close contact with the sidesurface of the light emitting diode element.

Therefore, in the light emitting diode device of the present inventionobtained by the above-described method, light emitted from the lightemitting diode element is reflected by the reflecting resin layer beforebeing absorbed by another member.

As a result, the extraction efficiency of the light can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view of one embodiment of a light emitting diodedevice of the present invention.

FIG. 2 shows process drawings for illustrating one embodiment of amethod for producing the light emitting diode device of the presentinvention:

(a) illustrating a step of preparing a reflecting resin sheet,

(b) illustrating a step of disposing the reflecting resin sheet on adiode board, and

(c) illustrating a step of allowing an exposed portion to be in contactwith the upper surface of a light emitting diode element.

FIG. 3 shows process drawings for illustrating one embodiment of amethod for producing the light emitting diode device of the presentinvention, subsequent to FIG. 2:

(d) illustrating a step of pressing the reflecting resin sheet,

(e) illustrating a step of peeling off a first release substrate, and

(f) illustrating a step of forming a phosphor layer.

FIG. 4 shows process drawings for illustrating the steps of preparingthe reflecting resin sheet in FIG. 2( a):

(a) illustrating a step of preparing the first release substrate,

(b) illustrating a step of disposing a mask on the first releasesubstrate, and

(c) illustrating a step of applying a reflecting resin composition ontothe first release substrate via the mask and subsequently, removing themask.

FIG. 5 shows a plan view of the mask disposed in the step in FIG. 4( b).

FIG. 6 shows process drawings for illustrating another embodiment (anembodiment in which a concave portion is provided in the first releasesubstrate) of a method for producing the light emitting diode device ofthe present invention:

(a) illustrating a step of providing a reflecting resin layer in theconcave portion in the first release substrate,

(b) illustrating a step of disposing the reflecting resin sheet on thediode board, and

(c) illustrating a step of laminating the reflecting resin sheet on thediode board to be pressed.

FIG. 7 shows process drawings for illustrating another embodiment (anembodiment in which the concave portion is provided in the first releasesubstrate) of a method for producing the light emitting diode device ofthe present invention, subsequent to FIG. 6:

(d) illustrating a step of peeling off the first release substrate and

(e) illustrating a step of forming the phosphor layer.

FIG. 8 shows process drawings for illustrating another embodiment (anembodiment in which the reflecting resin layer is directly provided onthe diode board) of a method for producing the light emitting diodedevice of the present invention:

(a) illustrating a step of providing the light emitting diode element inthe diode board,

(b) illustrating a step of providing the reflecting resin layer on thediode board, and

(c) illustrating a step of pressing the reflecting resin layer by apressing board.

FIG. 9 shows process drawings for illustrating another embodiment (anembodiment in which the reflecting resin layer is directly provided onthe diode board) of a method for producing the light emitting diodedevice of the present invention, subsequent to FIG. 8:

(d) illustrating a step of removing the pressing board and

(e) illustrating a step of providing the phosphor layer.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a plan view of one embodiment of a light emitting diodedevice of the present invention. FIGS. 2 and 3 show process drawings forillustrating one embodiment of a method for producing the light emittingdiode device of the present invention. FIG. 4 shows process drawings forillustrating the steps of preparing the reflecting resin sheet in FIG.2( a). FIG. 5 shows a plan view of the mask disposed in the step in FIG.4( b).

In FIGS. 1 and 3( f), a light emitting diode device 1 includes a diodeboard 2, a light emitting diode element 3 that is flip mounted on thediode board 2, a reflecting resin layer 4 that is formed at the lateralside of the light emitting diode element 3, and a phosphor layer 5 thatis provided on (one side in a thickness direction of) the light emittingdiode element 3.

A plurality of the light emitting diode devices 1 are provided at spacedintervals to each other in a plane direction (to be specific, aright-left direction of the paper surface and an up-down direction ofthe paper surface in FIG. 3 (f)).

The diode board 2 is formed into a generally flat plate shape. To bespecific, the diode board 2 is formed of a laminated board in which aconductive layer, as a circuit pattern, is laminated on an insulatingboard. The insulating board is formed of, for example, a silicon board,a ceramic board, a polyimide resin board, or the like. Preferably, theinsulating board is formed of the ceramic board, to be specific, asapphire (Al₂O₃) board. The conductive layer is formed of, for example,a conductor such as gold, copper, silver, or nickel. The conductors canbe used alone or in combination.

The conductive layer includes a terminal 6.

The terminals 6 are formed at spaced intervals in the plane direction onthe upper surface of the insulating board and are formed into a patterncorresponding to an electrode portion 8 to be described later. Althoughnot shown, the terminal 6 is electrically connected to an electric powersupply portion via the conductive layer.

The light emitting diode element 3 is provided on the upper surface (onesurface in the thickness direction) of the diode board 2 and is formedinto a generally rectangular shape in plane view. A plurality of thelight emitting diode elements 3 are, on the upper surface of one pieceof the diode board 2, provided at spaced intervals to each other in theplane direction.

The light emitting diode element 3 includes a light semiconductor layer7 and the electrode portion 8 that is formed on the lower surfacethereof.

The light semiconductor layer 7 is formed into a generally rectangularshape in plane view corresponding to the outer shape of the lightemitting diode element 3 and is formed into a generally rectangularshape in sectional view that is long in the plane direction.

Although not shown, for example, the light semiconductor layer 7includes a buffer layer, an N-type semiconductor layer, a light emittinglayer, and a P-type semiconductor layer that are sequentially laminatedin the thickness direction. The light semiconductor layer 7 is formed ofa known semiconductor material and is formed by a known growth methodsuch as an epitaxial growth method. The light semiconductor layer 7 hasa thickness in the range of, for example, 0.1 to 500 μm, or preferably0.2 to 200 μm.

The electrode portion 8 is electrically connected to the lightsemiconductor layer 7 and is formed so as to be included in the lightsemiconductor layer 7 when projected in the thickness direction. Theelectrode portion 8 includes, for example, an anode electrode that isconnected to the P-type semiconductor layer and a cathode electrode thatis formed in the N-type semiconductor layer.

The electrode portion 8 is formed of a known conductive material and hasa thickness in the range of, for example, 10 to 1000 nm.

The reflecting resin layer 4 is, on the upper surface of the diode board2, formed in a region (a board-side reflecting region) 10 other than aregion (a board-side diode region) 9 where the light emitting diodeelements 3 are formed in plane view.

The board-side reflecting region 10 is, around the board-side dioderegion 9, a region that is defined at the outer side thereof by theboard-side diode region 9. The board-side reflecting region 10 is formedof a region extending in a front-rear direction and a region extendingin the right-left direction, and is formed into a generally grid shapein plane view where the regions are perpendicular (intersectional) toeach other.

The reflecting resin layer 4 is provided at the outer side of the lightemitting diode element 3, to be specific, at the both outer sides in theright-left direction and the both outer sides in the front-reardirection of each of the light emitting diode elements 3.

As shown in FIG. 3( f), the reflecting resin layer 4 is in close contactwith the outer side surfaces of the light emitting diode element 3, tobe specific, each of the surfaces of the left surface, the rightsurface, the front surface (ref: FIG. 1), and the rear surface (ref:FIG. 1) of each of the light emitting diode elements 3. In this way, thereflecting resin layer 4 exposes the upper surface of the light emittingdiode element 3.

As shown in FIG. 1, the reflecting resin layer 4 is integrally formed tobe continuous. Therefore, for example, as shown in FIG. 3( f), in thereflecting resin layer 4 formed between two pieces of the light emittingdiode elements 3 (3A and 3B) that are disposed at spaced intervals toeach other in the right-left direction, the left end portion thereof isin close contact with the right end surface of a light emitting diodeelement 3A disposed at the left side of the reflecting resin layer 4 andthe right end portion thereof is in close contact with the left endsurface of a light emitting diode element 3B disposed at the right sideof the reflecting resin layer 4. As referred in FIG. 1, in the samemanner as the description above, the reflecting resin layer 4 formedbetween two pieces of the light emitting diode elements 3 that aredisposed at spaced intervals to each other in the front-rear directionis in close contact with the front surface and the rear surface of thelight emitting diode elements 3, respectively. To be specific, the frontend portion and the rear end portion of the reflecting resin layer 4 arerespectively in close contact with the front surface and the rearsurface of the light emitting diode elements 3 that are respectivelydisposed at the front side and the rear side of the reflecting resinlayer 4.

As shown in FIG. 3( f), a resin concave portion 11, which is formed by apressing (ref: an arrow in FIG. 3( d)) of a reflecting resin sheet 13 tobe described later, is formed at the upper surface of the reflectingresin layer 4.

That is, in the reflecting resin layer 4, the upper surface of the resinconcave portion 11 is formed into a flat state and a portion formed atthe circumference end portion of the light emitting diode element 3 isformed to be higher than the resin concave portion 11.

The above-described reflecting resin layer 4 contains, for example, alight reflecting component. To be specific, the reflecting resin layer 4is formed of a reflecting resin composition that contains a resin andthe light reflecting component.

An example of the resin includes a thermosetting resin such asthermosetting silicone resin, epoxy resin, thermosetting polyimideresin, phenol resin, urea resin, melamine resin, unsaturated polyesterresin, diallyl phthalate resin, and thermosetting urethane resin.Preferably, the thermosetting silicone resin or the epoxy resin is used.

The light reflecting component is, for example, a white compound. To bespecific, an example of the white compound includes a white pigment.

An example of the white pigment includes a white inorganic pigment.Examples of the white inorganic pigment include an oxide such astitanium oxide, zinc oxide, and zirconium oxide; a carbonate such aswhite lead (lead carbonate) and calcium carbonate; and a clay mineralsuch as kaolin (kaolinite).

As the white inorganic pigment, preferably, the oxide is used or morepreferably, the titanium oxide is used.

The titanium oxide can have characteristics such as a high degree ofwhiteness, a high light reflectivity, excellent hiding characteristics(hiding power), excellent coloring characteristics (coloring power), ahigh dispersibility, an excellent weather resistance, and a highchemical stability.

To be specific, the titanium oxide is TiO₂ (titanium oxide (IV),titanium dioxide).

A crystal structure of the titanium oxide is not particularly limited.For example, the crystal structure thereof is rutile, brookite(pyromelane), anatase (octahedrite), or the like. Preferably, thecrystal structure thereof is rutile.

A crystal system of the titanium oxide is not particularly limited. Forexample, the crystal system thereof is a tetragonal system, anorthorhombic system, or the like. Preferably, the crystal system thereofis the tetragonal system.

When the crystal structure and the crystal system of the titanium oxideare rutile and the tetragonal system, respectively, it is possible toeffectively prevent a reduction of the reflectance with respect to light(to be specific, visible light, among all, the light around thewavelength of 450 nm) even in a case where the reflecting resin layer 4is exposed to a high temperature for a long time.

The light reflecting component is in the form of a particle. The shapethereof is not limited and examples of the shape thereof include, forexample, a sphere shape, a plate shape, and a needle shape. An averagevalue of the maximum length (in a case of the sphere shape, the averageparticle size) of the light reflecting component is in the range of, forexample, 1 to 1000 nm. The average value of the maximum length ismeasured by using a laser diffraction scattering particle size analyzer.

The mixing ratio of the light reflecting component per 100 parts by massof the resin is, for example, 0.5 to 90 parts by mass, or preferably 1.5to 70 parts by mass from the viewpoint of the coloring characteristics,the light reflectivity, and handling ability of the reflecting resincomposition.

The above-described light reflecting component is uniformly dispersedand mixed into the resin.

In addition, a filler can further be added into the reflecting resincomposition. That is, the filler can be used in combination with thelight reflecting component (to be specific, the white pigment).

An example of the filler includes a known filler, except for theabove-described white pigment. To be specific, an inorganic filler isused. Examples thereof include silica powder, talc powder, aluminapowder, aluminum nitride powder, and silicon nitride powder.

Preferably, as the filler, the silica powder is used from the viewpointof reducing a linear expansion coefficient of the reflecting resin layer4.

Examples of the silica powder include fused silica powder andcrystalline silica powder. Preferably, the fused silica powder (that is,silica glass powder) is used.

Examples of the shape of the filler include, for example, a sphereshape, a plate shape, and a needle shape. Preferably, the sphere shapeis used from the viewpoint of excellent filling characteristics andfluidity.

Therefore, preferably, the fused silica powder in a sphere shape is usedas the silica powder.

The average value of the maximum length (in a case of the sphere shape,the average particle size) of the filler is in the range of, forexample, 5 to 60 μm, or preferably 15 to 45 μm. The average value of themaximum length is measured by using the laser diffraction scatteringparticle size analyzer.

The addition ratio of the filler is adjusted so that the total amount ofthe filler and the light reflecting component per 100 parts by mass ofthe resin is, for example, 10 to 80 parts by mass. And the additionratio of the filler is adjusted so that the total amount of the fillerand the light reflecting component per 100 parts by mass of the resin ispreferably 25 to 75 parts by mass, or more preferably 40 to 60 parts bymass from the view point of reducing the linear expansion coefficientand ensuring the fluidity.

The above-described resin, light reflecting component, and filler, whichis added as required, are blended to be uniformly mixed, so that thereflecting resin composition is prepared.

The reflecting resin composition is prepared in a B-stage state.

The reflecting resin composition is formed, for example, in a state ofliquid or semi-solid and has a kinetic viscosity in the range of, forexample, 10 to 30 mm²/s.

In this way, the outer side surfaces of the light emitting diode element3 are encapsulated by the reflecting resin layer 4.

At the lower side of the light semiconductor layer 7, a lower space 12(ref: FIG. 2( b)) corresponding to the thickness of the electrodeportion 8 is formed. The reflecting resin layer 4 is filled in the lowerspace 12, and the reflecting resin layer 4 is in close contact with thelower surface of the light semiconductor layer 7 exposed from theelectrode portion 8 and the side surfaces of the electrode portion 8.

As shown in FIG. 3( f), a thickness T1 of the end portion of thereflecting resin layer 4 is the same as the above-described thickness ofthe light emitting diode element 3 (the total thickness of the lightsemiconductor layer 7 and the electrode portion 8). A thickness T2 ofthe central portion of the reflecting resin layer 4 with respect to thethickness T1 of the end portion is in the range of, for example, 50% ormore, preferably 90% or more, or more preferably 95% or more, andusually less than 100% and to be specific, in the range of, for example,10 to 500 μm, or preferably 15 to 500 μm.

The phosphor layer 5 is formed on the entire surface of the uppersurface (one surface in the thickness direction) of the light emittingdiode element 3 and is formed into the same pattern as that of the outershape of the light emitting diode element 3 when projected in thethickness direction.

The phosphor layer 5 is formed of, for example, a phosphor compositionthat contains a phosphor.

Preferably, the phosphor composition contains the phosphor and theresin.

An example of the phosphor includes a yellow phosphor that is capable ofconverting blue light into yellow light. An example of the phosphorincludes a phosphor obtained by doping a metal atom such as cerium (Ce)or europium (Eu) into a composite metal oxide, a metal sulfide, or thelike.

To be specific, examples of the phosphor include garnet type phosphorhaving a garnet type crystal structure such as Y₃Al₅O₁₂:Ce (YAG (yttriumaluminum garnet):Ce), (Y, Gd)₃Al₅O₁₂:Ce, Tb₃Al₃O₁₂:Ce, Ca₃Sc₂Si₃O₁₂:Ce,and Lu₂CaMg₂(Si, Ge)₃O₁₂:Ce; silicate phosphor such as (Sr, Ba)₂SiO₄:Eu,Ca₃SiO₄Cl₂:Eu, Sr₃SiO₅:Eu, Li₂SrSiO₄:Eu, and Ca₃Si₂O₇:Eu; aluminatephosphor such as CaAl₁₂O₁₉:Mn and SrAl₂O₄:Eu; sulfide phosphor such asZnS:Cu,Al, CaS:Eu, CaGa₂S₄:Eu, and SrGa₂S₄:Eu; oxynitride phosphor suchas CaSi₂O₂N₂:Eu, SrSi₂O₂N₂:Eu, BaSi₂O₂N₂:Eu, and Ca-a-SiAlON; nitridephosphor such as CaAlSiN₃:Eu and CaSi₅N₈:Eu; and fluoride-based phosphorsuch as K₂SiF₆:Mn and K₂TiF₆:Mn. Preferably, garnet type phosphor isused, or more preferably, Y₃Al₅O₁₂:Ce (YAG) is used.

The phosphors can be used alone or in combination of two or more.

The mixing ratio of the phosphor is, for example, 1 to 50 mass %, orpreferably 5 to 30 mass % with respect to the phosphor composition. Themixing ratio of the phosphor is, for example, 1 to 100 parts by mass, orpreferably 5 to 40 parts by mass per 100 parts by mass of a resin.

The resin is a matrix in which the phosphor is dispersed, including, forexample, transparent resins such as silicone resin, epoxy resin, andacrylic resin. Preferably, the silicone resin is used from the viewpointof durability.

The silicone resin has, in its molecule, a main chain mainly composed ofthe siloxane bond (—Si—O—Si—) and a side chain, which is bonded tosilicon atoms (Si) of the main chain, composed of an organic group suchas an alkyl group (for example, a methyl group and the like) or analkoxyl group (for example, a methoxy group).

To be specific, examples of the silicone resin include dehydrationcondensation type silicone resin, addition reaction type silicone resin,peroxide curable silicone resin, moisture curable silicone resin, andcurable silicone resin. Preferably, the addition reaction type siliconeresin is used.

The silicone resin has a kinetic viscosity at 25° C. in the range of,for example, 10 to 30 mm²/s.

The resins can be used alone or in combination of two or more.

The mixing ratio of the resin is, for example, 50 to 99 mass %, orpreferably 70 to 95 mass % with respect to the phosphor composition.

The phosphor and the resin are blended at the above-described mixingratio and are stirred and mixed, so that the phosphor composition isprepared.

Next, a method for producing the above-described light emitting diodedevice 1 is described with reference to FIGS. 2 to 5.

In this method, as shown in FIG. 2( a), the reflecting resin sheet 13 isfirst prepared.

The reflecting resin sheet 13 is a transfer sheet for providing thereflecting resin layer 4 on the lateral sides of the light emittingdiode element 3. The reflecting resin sheet 13 is formed into a patternof being capable of being in close contact with the light emitting diodeelement 3 in a pressing to be described later (FIG. 3( d)) correspondingto the above-described light emitting diode element 3.

The reflecting resin sheet 13 includes a first release substrate 14 as arelease substrate and the reflecting resin layer 4 that is provided onthe upper surface (one surface in the thickness direction) thereof.

The reflecting resin sheet 13 can be obtained by allowing the reflectingresin layer 4 to be provided on the upper surface of the first releasesubstrate 14.

To provide the reflecting resin layer 4 on the upper surface of thefirst release substrate 14, as shown in FIG. 4( a), the first releasesubstrate 14 is first prepared.

The first release substrate 14 is, for example, a release sheet (arelease film) in a generally rectangular shape and the upper surface andthe lower surface thereof are formed into a flat state.

The first release substrate 14 is formed of a resin material and thelike such as a vinyl polymer including polyolefin (to be specific,polyethylene and polypropylene) and ethylene-vinyl acetate copolymer(EVA); a polyester including polyethylene terephthalate andpolycarbonate; and a fluorine resin including polytetrafluoroethylene.The first release substrate 14 is also formed of a metal material suchas iron, aluminum, or stainless steel.

The first release substrate 14 can also be formed of a thermal releasesheet that can be easily peeled off from the reflecting resin layer 4 bybeing heated. As shown in phantom lines in FIG. 4( a), for example, thethermal release sheet includes a supporting layer 15 and apressure-sensitive adhesive layer 16 that is laminated on the uppersurface of the supporting layer 15.

The supporting layer 15 is formed of, for example, a heat resistantresin such as polyester.

The pressure-sensitive adhesive layer 16 is formed of, for example, athermally expandable pressure-sensitive adhesive and the like, which hasadhesion under normal temperature (25° C.), and in which the adhesion isreduced (or lost) at the time of being heated.

A commercially available product can be used as the above-describedthermal release sheet. To be specific, REVALPHA (a trade name,manufactured by NITTO DENKO CORPORATION) and the like can be used.

The thermal release sheet reliably supports the reflecting resin layer 4by the supporting layer 15 via the pressure-sensitive adhesive layer 16and is peeled off from the reflecting resin layer 4 due to a reductionin the adhesion of the pressure-sensitive adhesive layer 16 by theheating and thermal expansion performed thereafter.

The first release substrate 14 has a thickness in the range of, forexample, 10 to 1000 μm.

Next, as shown in FIG. 4( b), a mask 20 is disposed on the first releasesubstrate 14 (one side in the thickness direction).

As shown in FIG. 5, the mask 20 is formed into a pattern of integrallyincluding a frame portion 17, a covering portion 18 that is disposed atspaced intervals to the inner side of the frame portion 17 in the planedirection, and a bridge portion 19 that is disposed between the frameportion 17 and the covering portion 18.

The frame portion 17 is formed into a generally rectangular frame shapein plane view. The frame portion 17 is formed to have a width that cansupport the covering portion 18 via the bridge portion 19 (a widthcapable of ensuring strength).

A plurality of the covering portions 18 are disposed at spaced intervalsto each other so as to correspond to the above-described light emittingdiode elements 3 (ref: FIG. 1). That is, each of the covering portions18 is formed independently.

The outer shape of the covering portion 18 is formed into a similarshape (to be specific, a generally rectangular shape in plane view)having a size slightly larger than that of the light emitting diodeelement 3 in plane view. A maximum length L1 of the covering portion 18is in the range of L2 (a maximum length of the light emitting diodeelement 3)+0.22 mm or less, or preferably L2+0.15 mm or less, andusually, for example, L2 or more and to be specific, in the range of,for example, 0.3 to 3 mm, or preferably 0.42 to 2.1 mm.

The bridge portion 19 is disposed between the frame portion 17 and thecovering portion 18, and is also disposed between the covering portions18 that are adjacent to each other in the plane direction. Each of thebridge portions 19 is formed into a generally X-shape in plane view andis, for example, disposed between four pieces of the covering portions18 (18A, 18B, 18C, and 18D) that are adjacent to each other in the planedirection so as to connect the end portions thereof in the right-leftdirection and the front-rear direction.

The bridge portion 19 is, for example, formed of a linear member such asa wire. The bridge portion 19 is formed to have a width that issignificantly narrow with respect to the maximum length L1 of thecovering portion 18. To be specific, the width thereof is in the rangeof, for example, 100 μm or less, or preferably 50 μm or less, andusually, for example, 25 μm or more.

The mask 20 is formed of, for example, a metal material such asstainless steel and iron or a resin material such as polyethyleneterephthalate. Preferably, the mask 20 is formed of the metal material.

The mask 20 is formed into the above-described pattern by, for example,a known pattern forming method such as an etching or a laser processing.

The mask 20 has a thickness in the range of, for example, 20 to 500 μm.

As shown in FIG. 4( b), the above-described mask 20 is disposed (placed)on the upper surface of the first release substrate 14 so that thecovering portion 18 is disposed in opposed relation in the thicknessdirection to a region (a release-substrate-side diode region) 21corresponding to the board-side diode region 9 on the upper surface ofthe first release substrate 14 (ref: FIG. 2( b)). The covering portion18 is disposed in opposed relation to the release-substrate-side dioderegion 21 so that the circumference end portion thereof surrounds therelease-substrate-side diode region 21 in plane view.

Next, in this method, as shown in FIG. 4( c), the reflecting resincomposition is applied onto the first release substrate 14 via the mask20.

In the application of the reflecting resin composition, for example, anapplication method such as printing and dispenser is used.

In this way, a reflecting film 22 made of the reflecting resincomposition is formed on the upper surface of the first releasesubstrate 14 in a pattern reverse to that of the mask 20. The reflectingfilm 22 is also formed on the upper surface of the mask 20.

Subsequently, as shown by the arrows in the phantom lines in FIG. 4( c),the mask 20 is removed from the first release substrate 14. To bespecific, the mask 20 is pulled toward the upper side.

By pulling the mask 20 toward the upper side, the reflecting film 22that is formed on the upper surface of the covering portion 18 isremoved.

By the above-described pulling up of the mask 20, the reflecting film 22around the bridge portion 19 (ref: FIG. 5) (to be specific, thereflecting resin composition formed on the side surfaces of the bridgeportion 19) slightly moves, so that the region where the bridge portion19 is disposed is covered (filled in) with the reflecting film 22without being exposed.

In this way, as shown in FIG. 2( a), the reflecting film 22 is formed ina pattern (ref: FIG. 2( b)) reverse to that of the covering portion 18(ref: FIG. 5). That is, the reflecting film 22 is, on the upper surfaceof the first release substrate 14, formed in a region (arelease-substrate-side reflecting region) 23 corresponding to theboard-side reflecting region 10.

The reflecting film 22 in the above-described pattern is heated(described later), so that the reflecting resin layer 4 in theabove-described pattern in a B-stage state is obtained.

As referred in FIG. 2( b) to be described later, the reflecting resinlayer 4 is formed in such a pattern that when the reflecting resin sheet13 is turned over upside down and the turned over reflecting resin sheet13 is disposed in opposed relation to the diode board 2, the lowersurface of the first release substrate 14 exposed from the reflectingresin layer 4 (an exposed portion 25), when projected in the thicknessdirection, includes the light emitting diode element 3. To be morespecific, as referred in FIG. 2( c) to be described later, thereflecting resin layer 4 is formed in a pattern of being in contact withthe diode board 2 when the reflecting resin sheet 13 is laminated on thediode board 2 to be described next.

In this way, the reflecting resin sheet 13 including the reflectingresin layer 4 and the first release substrate 14 is obtained.

Separately, in this method, as shown in the lower portion in FIG. 2( b),the light emitting diode element 3 is provided on the upper surface (onesurface in the thickness direction) of the diode board 2.

To be specific, the electrode portion 8 is electrically connected to theterminal 6 and the light emitting diode element 3 is flip-chip mounted(flip-chip mounting is also called flip mounting) on the diode board 2.

Next, in this method, as shown in FIG. 2( b), the reflecting resin sheet13 is disposed in opposed relation to the upper side of the diode board2.

To be specific, the reflecting resin sheet 13 is first turned overupside down from the state shown in FIG. 2( a) and subsequently, thereflecting resin layer 4 is disposed so as to be opposed to theboard-side reflecting region 10 on the upper surface of the diode board2.

On the upper surface of the first release substrate 14, a buffer sheet26 is provided.

The buffer sheet 26 is a sheet (a cushion sheet) that buffers a pressingforce so as not to allow the pressing force to non-uniformly apply tothe light emitting diode element 3 in the pressing to be described next(ref: the arrow in FIG. 3( d)). The buffer sheet 26 is formed of, forexample, an elastic sheet (film) and the like.

A buffer material for forming the buffer sheet 26 includes the sameresin material as that for forming the first release substrate 14described above. Preferably, the buffer sheet 26 is formed of vinylpolymer, or more preferably, the buffer sheet 26 is formed of EVA.

The buffer sheet 26 has a thickness in the range of, for example, 0.01to 1 mm, or preferably 0.05 to 0.2 mm.

Next, in this method, as shown in FIGS. 2( c) and 3(d), the reflectingresin sheet 13 is laminated on the diode board 2.

That is, as shown in FIG. 2( c), the lower surface of the reflectingresin layer 4 is first allowed to be in contact with the board-sidereflecting region 10 in the diode board 2 and the exposed portion 25 isallowed to be in contact with the upper surface of the light emittingdiode element 3.

That is, both of the reflecting resin layer 4 and the light emittingdiode element 3 are sandwiched between the first release substrate 14and the diode board 2 in the thickness direction.

At the time of the contact described above, a minute side space 27 isformed between the reflecting resin layer 4 and the light emitting diodeelement 3 in the plane direction. The side space 27 is formed as a spacethat slightly separates the reflecting resin layer 4 from the lightemitting diode element 3 in the plane direction.

Subsequently, as shown in the arrow in FIG. 3( d), the reflecting resinsheet 13 is pressed toward the lower side.

To be specific, the reflecting resin sheet 13 with respect to the diodeboard 2 is pressed via the buffer sheet 26, for example, with a pressingmachine or the like.

The pressure is in the range of, for example, 0.01 to 7 MPa, orpreferably 0.05 to 4 MPa.

The above-described pressing can be performed together with heating asrequired. That is, hot pressing (to be specific, hot pressing in whichthe pressing is performed with a hot plate) can be performed.

The heating temperature is in the range of, for example, 25 to 140° C.

In this way, the exposed portion 25 of the first release substrate 14 isin close contact with the upper surface (one surface in the thicknessdirection) of the light emitting diode element 3.

With this, the reflecting resin layer 4 moves toward the side, to bespecific, toward the outer side in the plane direction (the left side,the right side, the front side, and the rear side). Therefore, the sidespace 27 (ref: FIG. 2( c)) is filled in with the reflecting resin layer4. The lower space 12 (ref: FIG. 2( c)) is also filled in with thereflecting resin layer 4.

In this way, the reflecting resin layer 4 is in close contact with theside surfaces (the left surface, the right surface, the front surface,and the rear surface) of the light emitting diode element 3.

The resin concave portion 11 is formed in the reflecting resin layer 4.

Next, as shown in FIG. 3( e), the first release substrate 14 is peeledoff from the reflecting resin layer 4 and the light emitting diodeelement 3. The first release substrate 14 is removed together with thebuffer sheet 26.

In this way, the reflecting resin layer 4 is transferred from the firstrelease substrate 14 to the diode board 2.

Thereafter, the reflecting resin layer 4 in a B-stage state is heated tobe cured.

The heating temperature is in the range of, for example, 40 to 150° C.,or preferably 50 to 140° C. The heating time is in the range of, forexample, 1 to 60 minutes, or preferably 3 to 20 minutes.

Next, as shown in FIG. 3( f), the phosphor layer 5 is provided on theupper surface of the light emitting diode element 3.

To provide the phosphor layer 5, for example, the above-describedphosphor composition is first applied onto the upper surface of thelight emitting diode element 3 in the above-described pattern to form aphosphor film (not shown).

Thereafter, the phosphor film is heated, for example, at 50 to 150° C.to be dried, so that the phosphor film is formed into theabove-described pattern.

In this way, the light emitting diode device 1 including the diode board2, the light emitting diode element 3 that is flip mounted on the diodeboard 2, the reflecting resin layer 4 that is in close contact with theside surfaces of the light emitting diode element 3, and the phosphorlayer 5 that is provided on the upper surface of the light emittingdiode element 3 is obtained as an assembly sheet.

Thereafter, as shown in dashed lines in FIG. 3( f), the reflecting resinlayer 4 and the diode board 2 that is formed thereunder, which arelocated between the light emitting diode elements 3, are subjected to acutting (dicing) process. That is, the reflecting resin layer 4 and thediode board 2 are subjected to the dicing process along the thicknessdirection, so that the light emitting diode elements 3 are cut intoplural pieces. That is, the light emitting diode elements 3 areindividualized (singulated).

According to the above-described method, as shown in FIG. 3( d), thereflecting resin sheet 13 is laminated on the diode board 2 so that thereflecting resin layer 4 is in close contact with the side surfaces ofthe light emitting diode element 3.

Therefore, in the light emitting diode device 1 obtained by theabove-described method, light emitted from the light emitting diodeelement 3 is reflected by the reflecting resin layer 4 before beingabsorbed by another member.

As a result, the extraction efficiency of the light can be improved.

In addition, in the embodiment in FIG. 3( d), the exposed portion 25 ofthe first release substrate 14 is allowed to be in close contact withthe upper surface of the light emitting diode element 3, so that it ispossible to prevent an infiltration (an inflow) of the reflecting resinlayer 4 into the upper surface of the light emitting diode element 3.Therefore, as shown in FIG. 3( f), the phosphor layer 5 can be directlylaminated on the upper surface of the light emitting diode element 3.

As a result, it is possible to reliably prevent the light, which isemitted from the light emitting diode element 3 toward the upper side,from being reflected toward the lower side and/or the side by thereflecting resin layer 4, and the light is efficiently converted inwavelength by the phosphor layer 5, so that the extraction efficiency ofthe light can be improved.

In the embodiments in FIGS. 4( b) and 4(c), the reflecting resin layer 4(ref: FIG. 2( a)) is formed using the mask 20. Alternatively, forexample, when the resin is the thermosetting resin in the form of apowder, as referred in FIG. 2( a), the resin composition is formed onthe entire upper surface of the first release substrate 14 by beingheated and subjected to compression molding to be cured with acompression molding machine. Thereafter, the reflecting resin layer 4can be formed into the above-described pattern by an etching and thelike.

On the other hand, when the reflecting resin layer 4 is formed using themask 20, it is possible to collect the reflecting resin composition,which adheres onto the upper surface of the mask 20 at the time ofpulling up the mask 20, as a material, so that the yield rate of thereflecting resin composition can be improved.

In the embodiments in FIGS. 2( b) to 3(f), the light emitting diodeelement 3 is flip mounted on the diode board 2 in advance and thereflecting resin layer 4 is transferred to the diode board 2.Alternatively, for example, as referred in a numeral 33 shown inparentheses in FIGS. 2( b) to 3(f), instead of the diode board 2, asecond release substrate 33 is first prepared and the light emittingdiode element 3 is provided on the upper surface thereof and then thereflecting resin layer 4 is transferred to the second release substrate33. Thereafter, the light emitting diode element 3 and the reflectingresin layer 4 can be transferred to the diode board 2, which isseparately prepared.

In that case, the second release substrate 33 is formed of the samerelease substrate as that of the first release substrate 14 describedabove.

In the above-described case, as referred in the numeral 33 shown inparentheses in FIGS. 2( b), the reflecting resin layer 4 is disposed onthe second release substrate 33. As referred in FIGS. 2 (c) and 3(d),the reflecting resin sheet 13 is disposed in opposed relation to thesecond release substrate 33 and subsequently, is pressed thereto, sothat the reflecting resin layer 4 is in close contact with the sidesurfaces of the light emitting diode element 3.

Thereafter, as referred in FIG. 3( e), the first release substrate 14 ispeeled off from the reflecting resin layer 4 (ref: FIG. 3( d)) and thelight emitting diode element 3 and subsequently, as referred in FIG. 3(f), the phosphor layer 5 is provided on the upper surface of the lightemitting diode element 3.

Next, as shown in the dashed lines in FIG. 3( f), the reflecting resinlayer 4 and the second release substrate 33 are subjected to the dicingprocess along the thickness direction, so that the light emitting diodeelements 3 are individualized (singulated).

Thereafter, as shown in the phantom lines in FIG. 3( f), the secondrelease substrate 33 is peeled off from the reflecting resin layer 4 andthe light emitting diode element 3. Next, the light emitting diodeelement 3 in which the side surfaces thereof are in close contact withthe reflecting resin layer 4 is flip mounted on the diode board 2, whichis referred in the lower portion in FIG. 2( b).

In this way, the light emitting diode device 1 is obtained.

According to the embodiment in which the second release substrate 33 isused, the same function effect as that of the embodiment in which thelight emitting diode element 3 is flip mounted on the diode board 2 inadvance can be obtained.

Furthermore, in the embodiment in which the second release substrate 33is used, it is not required that the light emitting diode element 3 isflip mounted on the diode board 2 in advance, so that the side surfacesof the light emitting diode element 3 can be easily in close contactwith the reflecting resin layer 4.

On the other hand, in the embodiment in which the light emitting diodeelement 3 is flip mounted on the diode board 2 in advance, after theside surfaces of the light emitting diode element 3, which is flipmounted on the diode board 2 in advance, are allowed to be in closecontact with the reflecting resin layer 4, the light emitting diodeelement 3 is not required to be separately flip mounted on the diodeboard 2, so that the light emitting diode device 1 can be easilyproduced.

In the process of pressing the reflecting resin sheet 13 shown by thearrow in FIG. 3( d), the reflecting resin sheet 13 with respect to thediode board 2 is pressed via the buffer sheet 26. Alternatively, asreferred in a numeral 28 shown in parentheses in FIG. 3( d), thereflecting resin sheet 13 can be directly hot pressed without providingthe buffer sheet 26 (ref: FIG. 2( c)).

In the hot pressing, as shown in FIG. 3( d), a hot plate 28 is usedinstead of the buffer sheet 26 and the first release substrate 14 ispressed with the hot plate 28 to perform the hot pressing.

In the embodiment in which the first release substrate 14 is pressedwith the hot plate 28, it is not required that the buffer sheet 26 isprovided in advance, so that the production processes can be simplified.

On the other hand, in the embodiment in which the reflecting resin sheet13 with respect to the diode board 2 is pressed via the buffer sheet 26,a damage of the light emitting diode element 3 caused by a non-uniformpressing force can be effectively prevented.

FIGS. 6 and 7 show process drawings for illustrating another embodiment(an embodiment in which a concave portion is provided in the firstrelease substrate) of a method for producing the light emitting diodedevice of the present invention.

In each figure to be described below, the same reference numerals areprovided for members corresponding to each of those described above, andtheir detailed description is omitted.

In the embodiments in FIGS. 3( e) and 3(f), the reflecting resin layer 4is formed so that the thickness thereof is the same or thinner than thatof the light emitting diode element 3. Alternatively, for example, asshown in FIGS. 7( d) and 7(e), the reflecting resin layer 4 can beformed so that the thickness thereof is thicker than that of the lightemitting diode element 3.

As shown in FIGS. 7( d) and 7(e), the reflecting resin layer 4 is formedso that an upper portion 29 protrudes from the light emitting diodeelement 3 toward the upper side when projected in the plane direction.The corners of the upper portion 29 are chamfered.

The thickness of the upper portion 29 with respect to that of the lightemitting diode element 3 is in the range of, for example, 100 to 200%,or preferably 150 to 200% and to be specific, in the range of, forexample, 20 to 1000 μm, or preferably 50 to 600 μm.

The phosphor layer 5 is formed, on the light emitting diode element 3,so as to be filled in between the upper portions 29 that are adjacent tothe light emitting diode elements 3.

Next, a method for producing the light emitting diode device 1 shown inFIG. 7( e) is described with reference to FIGS. 6 and 7.

In this method, as shown in FIG. 6( a), the reflecting resin sheet 13 isfirst formed.

To form the reflecting resin sheet 13, the first release substrate 14 isfirst prepared.

In the first release substrate 14, the release-substrate-side reflectingregion 23 is formed so as to be dented.

To be specific, on the upper surface (one surface in the thicknessdirection) of the first release substrate 14, the release-substrate-sidereflecting region 23 is defined as a concave portion 30 that is dentedtoward the lower side (the other side in the thickness direction) andthe release-substrate-side diode region 21 is defined as a protrudingportion 31 (the exposed portion 25) that protrudes from thecircumference end portion of the concave portion 30 toward the upperside.

That is, the first release substrate 14 is formed into a convexo-concaveshape in which the protruding portion 31 (the region corresponding tothe board-side reflecting region 10, ref: FIG. 1) is disposed into agenerally grid shape in plane view and the concave portions 30 (theregion corresponding to the board-side diode region 9, ref: FIG. 1) aresurrounded by the protruding portion 31.

The first release substrate 14 is formed, for example, by a knownmolding process such as an embossing process.

Next, as shown in FIG. 6( a), the reflecting resin layer 4 is providedon the upper surface of the first release substrate 14 according to thesame method as the description above.

In this way, the reflecting resin sheet 13 is formed.

Separately, as shown in the lower portion in FIG. 6( b), the lightemitting diode element 3 is flip mounted on the diode board 2.Subsequently, the reflecting resin sheet 13 is disposed in opposedrelation to the upper side of the diode board 2.

Next, as shown in FIG. 6( c), the reflecting resin sheet 13 is laminatedon the diode board 2 and subsequently, the reflecting resin sheet 13 ispressed (or hot pressed) with respect to the diode board 2.

By the above-described pressing, the reflecting resin layer 4 is formedso that the corners of the upper portion 29 are chamfered so as tocorrespond to the shape of the concave portion 30.

Next, as shown in FIG. 7( d), the first release substrate 14 (ref: FIG.6( c)) is peeled off from the reflecting resin layer 4 and the lightemitting diode element 3. Thereafter, as shown in FIG. 7( e), thephosphor layer 5 is, on the upper surface of the light emitting diodeelement 3, filled in between the upper portions 29 that are adjacent tothe light emitting diode elements 3.

In this way, the light emitting diode device 1 is obtained.

In the embodiment shown in FIG. 7( e), the same function effect as thatof the embodiment shown in FIG. 3( f) can be obtained.

In addition, in the embodiment shown in FIG. 7( e), the reflecting resinlayer 4 is formed so that the thickness thereof is thicker than that ofthe light emitting diode element 3, so that the light emitted from thelight emitting diode element 3 to the side obliquely upward can bereflected by the upper portion 29 in the reflecting resin layer 4.

As a result, the extraction efficiency of the light can be furtherimproved.

FIGS. 8 and 9 show process drawings for illustrating another embodiment(an embodiment in which the reflecting resin layer is directly providedon the diode board) of a method for producing the light emitting diodedevice of the present invention.

In the embodiments in FIGS. 2, 3, 6, and 7, the reflecting resin layer 4is transferred to the diode board 2 using the reflecting resin sheet(the transfer sheet) 13. Alternatively, for example, as shown in FIGS. 8and 9, the reflecting resin layer 4 can be directly provided on thediode board 2 without using the reflecting resin sheet (the transfersheet) 13.

Next, a method for obtaining the light emitting diode device 1 byproviding the reflecting resin layer 4 directly on the diode board 2 isdescribed with reference to FIGS. 8 and 9.

In this method, as shown in FIG. 8( a), the light emitting diode element3 is first provided on the upper surface (one surface in the thicknessdirection) of the diode board 2, which serves as a base member.

Next, as shown in FIG. 8( b), the reflecting resin layer 4 is, on theupper surface (one surface in the thickness direction) of the diodeboard 2, provided at the side of the light emitting diode element 3, tobe specific, at the outer side in the plane direction.

The reflecting resin layer 4 is provided so that the side space 27 isformed between the light emitting diode element 3 and the reflectingresin layer 4 in the plane direction.

To provide the reflecting resin layer 4 on the upper surface of thediode board 2, for example, a method such as an application of thereflecting resin composition via the mask 20 shown in FIG. 5, or acompression molding is used.

Next, in this method, as shown in the phantom lines in FIG. 8( c), apressing board 32 as a pressing member is prepared.

The pressing board 32 is formed into the same shape as that of the firstrelease substrate 14 in which the concave portion 30 and the protrudingportion 31 are provided, which is shown in FIG. 6( b).

The pressing board 32 is formed of the same material as that of thefirst release substrate 14 shown in FIG. 6( b). Preferably, the pressingboard 32 is formed of a metal material. The metal material can ensure areliable pressing when the reflecting resin layer 4 is pressed (ref:solid lines in FIG. 8( c)).

The lower surface of the pressing board 32 can be subjected to a knownrelease treatment (a surface treatment).

As shown in the phantom lines in FIG. 8( c), the pressing board 32 isdisposed above the diode board 2 so that the concave portion 30 isopposed to the reflecting resin layer 4 and the protruding portion 31 isopposed to the light emitting diode element 3.

Next, in this method, as shown by the arrow in the phantom lines and thesolid lines in FIG. 8( c), the reflecting resin layer 4 is pressed bythe pressing board 32.

To be specific, the pressing board 32 is lowered toward the diode board2, so that the protruding portion 31 is in close contact with the uppersurface of the light emitting diode element 3 and the concave portion 30presses the reflecting resin layer 4 toward the lower side.

In this way, the reflecting resin layer 4 comes into close contact witheach of the side surfaces of the light emitting diode element 3.

In the reflecting resin layer 4, the upper portion 29 that protrudesfrom the light emitting diode element 3 toward the upper side is formedinto a shape corresponding to the concave portion 30 in the pressingboard 32.

Next, as shown in FIG. 9( d), the pressing board 32 (ref: FIG. 8( c)) isremoved.

Next, as shown in FIG. 9( e), the phosphor layer 5 is, on the uppersurface of the light emitting diode element 3, filled in between theupper portions 29 that are adjacent to the light emitting diode elements3.

Thereafter, as shown in the dashed lines in FIG. 9( e), the reflectingresin layer 4 and the diode board 2 are subjected to the dicing processalong the thickness direction, so that the light emitting diode elements3 are individualized (singulated).

In this way, the light emitting diode device 1 is obtained.

In the embodiments in FIGS. 8 and 9, the reflecting resin layer 4 isprovided on the diode board 2 so as to be in close contact with the sidesurfaces of the light emitting diode element 3 without using thetransfer sheet (the reflecting resin sheet) 13, so that the productionprocesses can be simplified because of unnecessity of the preparationthereof.

On the other hand, in the embodiments in FIGS. 2, 3, 6, and 7, thereflecting resin layer 4 uses, as a transfer sheet, the reflecting resinsheet 13 that is formed in a predetermined pattern, so that thereflecting resin layer 4 can be reliably and easily provided on thediode board 2 so as to be in close contact with the side surfaces of thelight emitting diode element 3.

In the embodiments in FIGS. 8 and 9, as shown in FIG. 8( a), the basemember of the present invention is described as the diode board 2.Alternatively, for example, as referred in the numeral 33 shown inparentheses in FIGS. 8( a) to 9(e), the second release substrate 33 isused instead of the diode board 2 and the light emitting diode element 3can be directly provided on the upper surface thereof.

In that case, as referred in the numeral 33 shown in parentheses in FIG.8( a), the light emitting diode element 3 is provided on the uppersurface of the second release substrate 33, then as referred in FIG. 8(b), the reflecting resin layer 4 is laminated on the upper surface ofthe second release substrate 33, and subsequently as referred in FIG. 8(c), the pressing board 32 is pressed with respect to the reflectingresin layer 4 toward the lower side, so that the reflecting resin layer4 is in close contact with the side surfaces of the light emitting diodeelement 3.

Thereafter, as referred in FIG. 9( d), the pressing board 32 is removedand subsequently, as referred in FIG. 9( e), the phosphor layer 5 isprovided on the upper surface of the light emitting diode element 3.

Next, as shown in the dashed lines in FIG. 9( e), the reflecting resinlayer 4 and the second release substrate 33 are subjected to the dicingprocess along the thickness direction, so that the light emitting diodeelements 3 are individualized (singulated).

Thereafter, as referred in the phantom lines in FIG. 9( e), the secondrelease substrate 33 is peeled off from the reflecting resin layer 4 andthe light emitting diode element 3 and then, the light emitting diodeelement 3 in which the side surfaces thereof are in close contact withthe reflecting resin layer 4 is flip mounted on the diode board 2, whichis referred in FIG. 8( a).

In this way, the light emitting diode device 1 is obtained.

In the embodiment in which the base member is used as the second releasesubstrate 33, the same function effect as that of the embodiment inwhich the base member is used as the diode board 2 can be obtained.

In addition, in the embodiment in which the base member is used as thesecond release substrate 33, it is not required that the light emittingdiode element 3 is flip mounted on the diode board 2 in advance, so thatthe side surfaces of the light emitting diode element 3 can be easily inclose contact with the reflecting resin layer 4.

On the other hand, in the embodiment in which the base member is used asthe diode board 2, after the side surfaces of the light emitting diodeelement 3 are allowed to be in close contact with the reflecting resinlayer 4, the light emitting diode element 3 is not required to beseparately flip mounted on the diode board 2, so that the light emittingdiode device 1 can be easily produced.

EXAMPLES

While the present invention will be described hereinafter in furtherdetail with reference to Examples, the present invention is not limitedto these Examples.

Example 1 The Embodiments in FIGS. 2 and 3

First, a reflecting resin sheet was prepared (ref: FIG. 2( a)).

That is, a first release substrate in which the upper surface and thelower surface thereof are formed to be in a flat state made of afluorine resin having a thickness of 50 μm was prepared (ref: FIG. 4(a)).

Next, a mask made of stainless steel having a thickness of 100 μm wasdisposed on the upper surface of the first release substrate (ref: FIG.4( b)).

The mask was formed into a pattern of integrally including a frameportion, a covering portion, and a bridge portion (ref: FIG. 5). Thecovering portion was in a generally rectangular shape in plane view andhad a maximum length (L1) of 0.56 mm.

Next, a reflecting resin composition was prepared and the reflectingresin composition was applied onto the first release substrate via themask by a printing (ref: FIG. 4( c)).

100 parts by mass of thermosetting silicone resin and 20 parts by massof a particle of titanium oxide (TiO₂: tetragonal system of rutile) in asphere shape having an average particle size of 300 nm were uniformlymixed, so that the reflecting resin composition was prepared.

In this way, a reflecting film made of the reflecting resin compositionwas formed in a pattern reverse to that of the mask.

Subsequently, the mask was removed from the first release substrate(ref: arrows in phantom lines in FIG. 4( c)). In this way, thereflecting film around the bridge portion slightly moved, so that thereflecting film was disposed in the region where the bridge portion wasdisposed. In this way, the reflecting film was formed in a patternreverse to that of the covering portion. The reflecting film was in aB-stage state.

In this way, a reflecting resin sheet (a transfer sheet) including thefirst release substrate and a reflecting resin layer made of thereflecting film was formed.

Next, the first release substrate was turned over upside down and abuffer sheet made of EVA having a thickness of 0.12 mm was provided onthe upper surface of the first release substrate (ref: FIG. 2( b)).

Separately, a light emitting diode element, including a lightsemiconductor layer including the buffer layer (GaN); an N-typesemiconductor layer (n-GaN); a light emitting layer (InGaN); and aP-type semiconductor layer (p-GaN:Mg) and an electrode portion includingan anode electrode and a cathode electrode having a thickness of 0.1 mmand a maximum length (L2) of 0.42 mm, was flip mounted on the uppersurface of a diode board having a thickness of 1 mm (ref: the lowerportion in FIG. 2( b)). The diode board included an insulating boardmade of sapphire and a conductive layer including a terminal made ofcopper, nickel, and gold on the upper surface thereof.

Next, the reflecting resin sheet was laminated on the diode board (ref:FIGS. 2( c) and 3(d)).

To be specific, the lower surface of the reflecting resin layer wasallowed to be in contact with a board-side reflecting region in thediode board and an exposed portion was allowed to be in contact with theupper surface of the light emitting diode element (ref: FIG. 2( c)).

Next, the reflecting resin sheet was pressed toward the lower side (ref:the arrow in FIG. 3( d)). To be specific, the reflecting resin sheetwith respect to the diode board was pressed via the buffer sheet at apressure of 0.3 MPa with a pressing machine.

In this way, the exposed portion of the first release substrate cameinto close contact with the upper surface of the light emitting diodeelement and the reflecting resin layer came into close contact with theside surfaces of the light emitting diode element.

A resin concave portion was formed in the central portion on the uppersurface of the reflecting resin layer. The resin concave portion had athickness (T2) of 90 μm.

Next, the first release substrate was removed from the reflecting resinlayer and the light emitting diode element together with the buffersheet (ref: FIG. 3( e)).

In this way, the reflecting resin layer was transferred from the firstrelease substrate to the diode board.

Thereafter, the reflecting resin layer was cured by being heated.

Next, a phosphor layer was provided on the upper surface of the lightemitting diode element (ref: FIG. 3( f)).

To be specific, 26 parts by mass of phosphor particles composed ofY₃Al₅O₁₂:Ce (in a sphere shape, the average particle size of 8 μm) and74 parts by mass of a silicone resin (addition reaction type siliconeresin, kinetic viscosity (at 25° C.) of 20 mm²/S, manufactured by WACKERASAHIKASEI SILICONE CO., LTD.) were blended and stirred uniformly, sothat a phosphor composition was prepared.

Next, the prepared phosphor composition was applied onto the uppersurface of the light emitting diode element by a printing to form aphosphor film. Thereafter, the phosphor film was dried at 100° C. toform the phosphor layer.

Thereafter, the reflecting resin layer and the diode board weresubjected to a dicing process along a thickness direction, so that alight emitting diode device including the diode board, the lightemitting diode element, the reflecting resin layer, and the phosphorlayer was produced (ref: dashed lines in FIG. 3( f).

Example 2 The Embodiments in FIGS. 6 and 7

A light emitting diode device was produced in the same manner as inExample 1 except that a concave portion and a protruding portion wereformed on the upper surface of the first release substrate (ref: FIG. 6(a)) and the buffer sheet was not provided on the upper surface of thefirst release substrate.

That is, in the reflecting resin sheet, the reflecting resin layer wasformed in the concave portion in the first release substrate (ref: FIG.6( a)) and subsequently, the light emitting diode element was flipmounted on the diode board (ref: FIG. 6( b)). Next, the reflecting resinsheet was laminated on the diode board and then, the reflecting resinsheet was pressed with respect to the diode board (ref: FIG. 6( c)).

In this way, an upper portion of the reflecting resin layer was formedinto a taper shape corresponding to the concave portion.

Next, the first release substrate was peeled off from the reflectingresin layer and the light emitting diode element (ref: FIG. 7( d)) andthen, the phosphor layer was, on the upper surface of the light emittingdiode element, filled in between the upper portions that were adjacentto the light emitting diode elements (ref: FIG. 7( e)).

Thereafter, the reflecting resin layer and the diode board weresubjected to the dicing process along the thickness direction, so thatthe light emitting diode device was produced (ref: the dashed lines inFIG. 7( e)).

Example 3 The Embodiments in FIGS. 8 and 9

A light emitting diode device was obtained in the same manner as inExample 1 except that the reflecting resin layer was directly providedon the diode board (ref: FIG. 8( a)) without using the reflecting resinsheet (the transfer sheet) and a pressing board (ref: FIG. 8( c)) wasused in the pressing of the reflecting resin layer (ref: FIG. 9( e)).

That is, the light emitting diode element was first provided on theupper surface of the diode board (ref: FIG. 8( a)).

Next, the reflecting resin layer was provided on the upper surface ofthe diode board using the mask (ref: FIG. 5) so that a side space wasformed at the outer side in a plane direction of the light emittingdiode element (ref: FIG. 8( b)).

Next, in this method, the pressing board in which the concave portionand the protruding portion were provided made of stainless steel wasprepared (ref: the phantom lines in FIG. 8( c)).

Subsequently, the reflecting resin layer was pressed by the pressingboard (ref: the arrow in the phantom lines and solid lines in FIG. 8(c)).

In this way, the reflecting resin layer was allowed to be in closecontact with each of the side surfaces of the light emitting diodeelement and was formed, in the upper portion of the reflecting resinlayer, into a shape corresponding to the concave portion in the pressingboard.

Next, the pressing board was removed (ref: FIG. 9( d)) and then thephosphor layer was, on the upper surface of the light emitting diodeelement, filled in between the upper portions that were adjacent to thelight emitting diode elements (ref: FIG. 9( e)).

Thereafter, the reflecting resin layer and the diode board weresubjected to the dicing process along the thickness direction, so thatthe light emitting diode elements were singulated to obtain the lightemitting diode device (ref: the dashed lines in FIG. 9( e)).

While the illustrative embodiments of the present invention are providedin the above description, such is for illustrative purpose only and itis not to be construed as limiting the scope of the present invention.Modification and variation of the present invention that will be obviousto those skilled in the art is to be covered by the following claims.

What is claimed is:
 1. A reflecting resin sheet, for providing areflecting resin layer at the side of a light emitting diode element,comprising: a peelable substrate, and the reflecting resin layerprovided directly on a surface of the peelable substrate and extendingfrom the surface of the peelable substrate, wherein the reflecting resinlayer includes a plurality of through holes extending from the surfaceof the peelable substrate to an outer surface of the reflecting layerand each through hole is spaced apart from an adjacent through hole in apattern that accepts a light emitting diode element from a predeterminedarrangement of light emitting diode elements where side spaces areformed separating the reflecting resin layer from the light emittingdiode element, and the reflecting resin layer is in a B-stage state. 2.The reflecting resin sheet according to claim 1, wherein at one surfacein the thickness direction of the peelable substrate, a portion in whichthe reflecting resin layer is provided is dented toward the other sidein the thickness direction.
 3. The reflecting resin sheet according toclaim 1, wherein the peelable substrate is continuously formed without aspace in a direction perpendicular to the thickness direction.
 4. Thereflecting resin sheet according to claim 1, wherein the peelablesubstrate is formed of a resin material or a thermal peelable sheetcomprising a supporting layer and an adhesive layer laminated on theupper surface of the supporting layer.